A Textile-Integrated Polymer Thermoelectric Generator for Body Heat Harvesting

Integrating thermoelectric generators (TEGs) into textiles is attractive for body heat harvesting to power wearable electronics. Textile-integrated TEGs have the advantage of conformity to the body that ensures efficient heat transfer and does not impede movement. Additive printing techniques and solution processable polymer-based thermoelectric (TE) materials can be used for this purpose. However, a number of fabrication challenges limit the realization of a printed polymer-based textile TEG using a low cost, scalable, and textile compatible process. In this work, stencil and transfer printing techniques are successfully employed to fabricate a 32-leg device with a modest fill factor (approximate to 30%) on a commercial sports fabric substrate. PEDOT:PSS and Poly[Na(NiETT)] are formulated into inks and used as the p-type and the n-type polymer materials, respectively. The textile-integrated TE device yields an open circuit voltage of approximate to 3 mV at Delta T = 3 K. The fabrication process is scaled up to demonstrate an 864-leg device that yields a voltage output of approximate to 47 mV. This work is the first demonstration of a textile TEG based on p- and n-type conducting polymers capable of through-plane body heat harvesting. It serves as a proof-of-concept for integrating TE devices into mainstream fabrics and clothing.